1. Field of the Invention
The present invention concerns a shielded connector, and more precisely a shielded connector of the type comprising a plug and a socket designed to be attached to a flat support, notably a printed circuit board.
Numerous connections are known, designed to be attached by soldering to a printed circuit board provided with metallized holes.
The Applicant proposed in European Patent Application EP-A-0 649,195 a connection element having an insulating bridge piece with a "U" shaped section and elbow contact elements emerging inside the "U" structure on one end. The other end is inserted by force ("press fit") into the metallized holes of a printed circuit board. Moreover, according to one interesting characteristic, it has a rear insulating component surrounding the electrical contact elements in their bent part and a holding piece also inserted into the printed circuit board.
This connection element forms a socket designed to receive a plug of complementary shape. The arrangements used advantageously protect the bridge piece during vacuum soldering operations of the connection element and other components of the card.
For certain applications, it is necessary to have a connector that is insensitive to electromagnetic interference, notably when the signals carried are signals called "weak" and at high or very high frequency. To do this, the connector elements must be provided with a shielding. Moreover, a good ground continuity must be made between the two elements (plug and socket), on the one hand, and between the socket and the printed circuit card, on the other hand.
2. Prior Art
Shielded connection elements have been proposed, for example, in the patents U.S. Pat. No. 5,277,624 (Patrick CHAMPION et al.), U.S. Pat. No. 5,259,773 (Patrick CHAMPION et al.) or U.S. Pat. No. 5,356,301 (Patrick CHAMPION et al.). These modular connection elements permit creating electrical contacts from a mother card and/or a daughter card.
In order to create ground continuity, two elastic metallic projections in the form of a cross are provided, of one piece with the socket and cooperating with openings pierced in the walls facing the socket, so as to come into galvanic contact with the shielding of the corresponding plug. Although this pair of projections exerts a pressure force on the plug, the holding of the plug inside the socket is especially accomplished by inserting the male contact elements of one of the components (for example, the socket) into the female contacts of the other component (for example, the plug). In other words, the quality of the ground continuity can fluctuate.
The invention therefore has the primary goal of a good ground continuity between the socket and the plug.
In one preferred variant, it also has the goal of assuring a good ground continuity between the printed circuit supporting the socket and the plug.
This preferred variant of embodiment also retains, with regard to the socket, the essentials of the advantageous structure of the connection element according to the above-mentioned European Patent Application EP-A-0 649,195.
To do this, the shielding component comprises a principal body that is extended toward the front by projections (or sliding contacts) curved back on themselves, so as to make up a spring. This spring emerges inside the socket and exerts a pressure force on the plug.
In one preferred variant, when the connector has the structure described in the above-mentioned European Patent Application, the principal body is extended by a vertical wall folded back to form a horizontal plate. This latter comprises an opening designed to receive the holding piece of the bridge piece, before insertion of the latter into the printed circuit. According to this variant, the plate is joined to the socket, notably by this holding piece.
Advantageously, bent-back supplemental tabs are provided in the rear of the horizontal plate. The latter are inserted by force press fit! into metallized holes made in the printed circuit board. This variant therefore permits a good ground recovery on the printed circuit.
In one preferred variant of the invention, a second shielding is also provided, on the surface opposite the first.
The assembly does not perceptibly increase the complexity of manufacturing operations, nor the manufacturing costs.